OCE to measure the personnel performance？

Two perspectives of people performance are skill and attitude. KPI of skill is OCE (Overall contribution effeciency), or APQMIS，which is the abbreviation of Availability, Performance, Quality, Maitenance and improvement, Sustainability.
Generally, the skill KPI measurement can be deployed according to the steps in the followings:
A, Are the people available?
P, Have people perfromed?
Q, Time used enough?
MI, Production situation improved?
S, Level is suatainable or not?
For example:
A，If we have 100 time units in which the on duty time is 80 units, we can get the availability being 80/100 which equals 80%;
P，After the people is on duty or they come to company or working unit, they take 5 time units to attend training, 2.5 units standing by, 2.5 units preparing work reports and then do the normal activity work, the performance will be: P=(80-5-2.5-2.5)/80=87.5%;
Q，Let us presume the time usage rate being 90%;
MI，If MME before maintenance is 99% with post-Maintenance MME being 94%, then MI is 100%-(99%-94%)=95%;
S，We can use standard deviation to measure the sustainability of the people. For example, if it is 5, then S=(100-5)/100=95%;
so we get that OCE=80%*87.5%*90%*95%*95%=56.86%
We can see that it is very difficult to get a high OCE.